1. Field of the Invention
The present invention relates to a stationary vane unit of a rotary machine, a method of producing the stationary vane unit of the rotary machine, and a method of connecting the stationary vane unit of the rotary machine.
Priority is claimed on Japanese Patent Application No. 2011-042310, filed on Feb. 28, 2011, the content of which is incorporated herein by reference.
2. Description of the Related Art
Hitherto, for example, in a rotary machine such as a compressor and a turbine of a gas turbine, or a steam turbine and so on, a structure is known in which a stationary vane unit is disposed in the inner periphery of a casing extending along the outer periphery of a rotor. In the stationary vane unit, a plurality of stationary vane members is arranged around a central axis of rotation of the rotor for rotary machine, and outer shrouds formed in the outer peripheries of the stationary vane members are continuous in the circumferential direction so as to be connected to each other. As such a stationary vane unit, for example, as disclosed in JP-A-2009-2338, the outer shrouds connected to each other in an annular shape are connected to inner shrouds by welding, so that the plurality of stationary vane members is integrated with each other.
However, when the plurality of stationary vane members is integrated with each other by welding as described above, a large amount of welding heat is input to the outer shroud and the stationary vane body, so that they are thermally deformed. In order to prevent such adverse effect, in JP-A-2009-97370, a connection member which extends in the circumferential direction is provided along the outer peripheries of the outer shrouds connected to each other in the annular shape, and the connection member and the outer shrouds are welded to each other, so that the heat input to the outer shrouds and the stationary vane body is suppressed.